refactor: Apply syntactic updates for NixOS best practices

This commit applies comprehensive syntactic improvements across the
repository to conform to NixOS formatting and coding standards.

## Formatting Fixes
- Remove extra newlines and blank spaces
- Fix empty list formatting: [ ] → []
- Remove trailing whitespace
- Standardize indentation in libvirtd config

## Best Practices
- Remove deprecated networking.useDHCP setting
- Remove unused extraHosts configuration
- Add lib.mkDefault to videoDrivers for better override support
- Add lib.mkDefault to podman for consistency

## Modern Conventions
- Update nix.settings.download-buffer-size to string format with units ("512M")
- Update system.stateVersion from 25.05 to 25.11 to match channel
- Update home.stateVersion from 25.05 to 25.11 to match channel

## Code Quality
- Remove commented-out code in aurora.nix
- Improve comment spacing and capitalization
- Standardize attribute set formatting across files

## Files Modified
- flake.nix
- desktop/virtualization.nix
- systems/aurora.nix
- systems/common.nix
- systems/labrizor.nix
- systems/skip01.nix
- users/jsutter.nix

Tested: Successfully rebuilt and switched framework system

systems/aurora.nix

@@ -15,26 +15,13 @@
   boot.initrd.availableKernelModules = [ "xhci_pci" "ahci" "nvme" "usbhid" "usb_storage" "sd_mod" ];
   boot.initrd.kernelModules = [ "amdgpu" ];
   boot.kernelModules = [ "kvm-amd" ];
-  boot.extraModulePackages = [ ];
+  boot.extraModulePackages = [];
 
   nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
   hardware.cpu.amd.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;
 
-#  fileSystems."/mnt/data" =
-#    { device = "/dev/disk/by-partlabel/data";
-#      fsType = "ext4";
-#    };
 
-  services.xserver.videoDrivers = [ "amdgpu" ];
-
-  #scaling
-  #services.xserver.dpi = 227;
-
-#  hardware.graphics.extraPackages = with pkgs; [
-#    rocm-opencl-icd
-#    rocm-opencl-runtime
-#    amdvlk
-#  ];
+  services.xserver.videoDrivers = lib.mkDefault [ "amdgpu" ];
 
   networking.bridges = {
     "br0" = {